Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 84
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Drug Des Devel Ther ; 13: 3343-3355, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31571835

RESUMO

Objective: To investigate the effects of Chinese herb Danzhi Xiaoyao pills on the pharmacokinetics of venlafaxine and its metabolites O-desmethylvenlafaxine (ODV) and N-desmethylvenlafaxine (NDV) in beagles by using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods: Six beagles (half male, half female) were chosen to test, being fasted before the experiment but having free access to drinking water 1 day before being fed drugs. After oral administration of venlafaxine hydrochloride tablets (10.28 mg/kg), the blood samples were collected in succession at different points in time. After 1-week washout period, Danzhi Xiaoyao pills (0.6g/kg) were given through oral administration to the six beagles every morning until the 7th day, venlafaxine hydrochloride tablets (10.28 mg/kg) were given after feeding Danzhi Xiaoyao pills (0.6g/kg) half an hour and blood samples were collected continuously at different points. All samples were analyzed by UPLC-MS/MS, and the main pharmacokinetic parameters of venlafaxine, ODV and NDV were computed by DAS 2.0. Results: The Cmax of the venlafaxine group (control group) and the combination group (experimental group) were (2267.26±252.89) ng/mL and (1542.64±190.73) ng/mL, respectively. The AUC(0-∞) of the two groups were (13,934.79±3609.23) ng·h/mL and (8001.91±2167.58) ng·h/mL, respectively. The ODV Cmax of the two groups were (2253.80±215.81) ng/mL and (2721.37±118.20) ng/mL, and AUC(0-∞) were (13,974.99±2784.04) ng·h/mL and (17,539.44±1894.29) ng·h/mL, respectively. The NDV Cmax of the two groups were (50.98±5.76) ng/mL and (58.74±12.33) ng/mL, and AUC(0-∞) were (179.26±34.94) ng·h/mL and (220.68±51.41) ng·h/mL, respectively. After administration of Danzhi Xiaoyao pills, the Cmax and AUC(0-∞) of venlafaxine decreased significantly, indicating that the plasma exposure of venlafaxine decreased. The increase of Cmax and AUC(0-∞) of ODV and NDV indicated a rise in plasma exposure. Conclusion: Danzhi Xiaoyao pills can accelerate the metabolism of venlafaxine in beagles. In clinical, when venlafaxine was co-administrated with Danzhi Xiaoyao pills, dose adjustment of venlafaxine should be taken into account.

2.
Nat Commun ; 10(1): 3981, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31484922

RESUMO

The diverse expression pattern of CD36 reflects its multiple cellular functions. However, the roles of CD36 in colorectal cancer (CRC) remain unknown. Here, we discover that CD36 expression is progressively decreased from adenomas to carcinomas. CD36 loss predicts poor survival of CRC patients. In CRC cells, CD36 acts as a tumor suppressor and inhibits aerobic glycolysis in vitro and in vivo. Mechanically, CD36-Glypcian 4 (GPC4) interaction could promote the proteasome-dependent ubiquitination of GPC4, followed by inhibition of ß-catenin/c-myc signaling and suppression of downstream glycolytic target genes GLUT1, HK2, PKM2 and LDHA. Moreover, disruption of CD36 in inflammation-induced CRC model as well as ApcMin/+ mice model significantly increased colorectal tumorigenesis. Our results reveal a CD36-GPC4-ß-catenin-c-myc signaling axis that regulates glycolysis in CRC development and may provide an intervention strategy for CRC prevention.

4.
Carbohydr Polym ; 218: 315-323, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31221336

RESUMO

In this study, cellulosic fines were separated from corn stalk soda-anthraquinone (AQ) pulp, then dissolved in DMAc/LiCl solvent system and regenerated to form films. Pulp fines was separated from pulp fibers using different standard sieves. The results exhibited that the value of specific surface area for fines was increased with the reduction of particle size. The cellulose of fines was successfully dissolved in DMAc/LiCl solution and regenerated as biopolymeric films in the water bath. Mechanical properties of regenerated cellulose films were enhanced with the increase of raw-material fineness from 120 to 300 mesh. It was exhibited a remarkable decrease on the values of tensile strength and maximum decomposition temperature of the regenerated cellulose film from 500-mesh fines, indicating that too small dimensions of cellulosic particles took disadvantages on physical strength and thermostability.

5.
Sci Total Environ ; 687: 494-504, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31212158

RESUMO

Sewer sediment is the main source of overflow pollution, and the anti-scouribility of sewer sediment directly determines the amount of the discharged contaminants. In this study, sewer sediments of different depths were collected from combined and storm sewers in Shanghai, China. The anti-scouribility, represented by the shear stress of each layer of sewer sediment, was detected in situ. The microbial community and extracellular polymeric substances (EPS), including carbohydrates and proteins present in the sewer sediments were characterized. The results indicated that the distribution of the anti-scouribility of sewer sediment is regulated. There were positive correlations between the content of EPS, proteins, and carbohydrates, and the anti-scouribility of sediments (Pearson Corr. = 0.604, sig. = 0.219; Pearson Corr. = 0.623, sig. = 0.234; Pearson Corr. = 0.727, sig. = 0.359, respectively). Furthermore, the microbial community had a positive influence on anti-scouribility. In particular, the gram-positive bacterial phyla of Bacteroidetes and Firmicutes may be important and influential for the improvement of anti-scouribility of sediment owing to their production of cellulose.

6.
Carbohydr Polym ; 217: 190-198, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31079676

RESUMO

In this study, an improved facile cellulose dissolution with low chemical concentration process was used for preparing corn stalk pith regenerated cellulose (RC) films. The conventional method usually requires 68% zinc chloride solution for cellulose dissolution. The objective of this study is produced corn stalk pith RC films by using a low-concentration zinc chloride solution with improved thermal stability. The major weight loss peak temperature of RC films was increased from 231 °C to 307 °C as the crystallinity indexes increased from 48.30% to 53.19% by decreased the concentration of zinc chloride solution from 65% to 45%, respectively. The increased thermal stability can create new opportunities for the development of RC films dissolving by zinc chloride solution.


Assuntos
Celulose/química , Cloretos/química , Zea mays/química , Compostos de Zinco/química , Química Verde/métodos , Membranas Artificiais , Permeabilidade , Porosidade , Solubilidade , Vapor , Temperatura Ambiente , Resistência à Tração , Água/química
7.
Environ Monit Assess ; 191(6): 343, 2019 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-31055667

RESUMO

The characteristics of surface runoff and the infiltration properties of urban green land are important to determine the effects of runoff reduction by low-impact development (LID) facilities. In this paper, two typical types of urban green land (lawn and shrub) in Shanghai were selected to study the runoff characteristics under eight rainfall events. The sensitivity of the runoff parameters was analyzed, and then, the optimal parameters were determined using the Stormwater Management Model (SWMM). The results showed that the interception and infiltration capacities of shrub were greater than those of lawn. The rainfall intensity and rainfall pattern were the major factors that influenced the interception and infiltration of rainwater. The threshold value that generates runoff varied across the eight rainfall events ranged from 1.6 to 28.5 mm for lawn and 4.5 to 32.0 mm for shrub. The maximum reduction ratios of runoff and peak flow for shrub were 52 and 57% higher than them for lawn, respectively. The parameters for shrub were more sensitive to runoff and peak flow compared with those for lawn. Under light rainfalls with a short duration, the maximum infiltration rate and depression storage were more sensitive than those under heavy rainfalls with a long duration. Antecedent dry weather period was not found to be a sensitive parameter except for the shrub under light rainfalls. The relative errors of runoff and dynamic mean runoff (60 min) for lawn and shrub were within ± 9.5%. The errors of peak flow ranged between - 21 and 16.6%. The dynamic runoff characteristics and the parameters for lawn and shrub determined in this study can provide references for simulating urban runoff and planning LID areas.


Assuntos
Simulação por Computador , Drenagem Sanitária/métodos , Monitoramento Ambiental/métodos , Chuva , Movimentos da Água , Calibragem , China , Cidades , Poaceae/crescimento & desenvolvimento
8.
Carbohydr Polym ; 212: 229-234, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30832852

RESUMO

A strategy to realize a reinforced photothermal stability cellulose nanofibrils (CNFs) films was reported. The LDHs were dispersed homogeneously onto the active site of CNFs surface by electrostatic self-assembly and the Mg/Al LDHs armour-type nanofibrils were prepared. After simple vacuum filtration, this kind nanofibrils can fabricate highly ordered multilayer film. Suitable amount of additive can bring outstanding photo-thermal property. The visible-light transmittance of the composite films can reach to c.a 80.0% when addition was 0.1% wt. and folding strength of the films contained 0.5% wt LDHs can increased by 15 times. The strength and the light transmittancevery of composite films was also higher than the pure nanocellulose film with the photothermal radiometry for about 30 h under 60 °C drying condition. The production is simple and highly repeatable process could be a good reference for preparation of high photothermal stability and transparent CNFs-based thin films.

10.
BMC Cancer ; 18(1): 539, 2018 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-29739365

RESUMO

BACKGROUND: SETDB1 is a histone H3K9 methyltransferase, which plays a significant role in the occurrence and progression of tumors. Previous studies have confirmed that T-lymphom invasion and metastasis gene (Tiam1) is a protein associated with the metastasis of hepatocellular carcinoma (HCC); however, we have not yet been successful in elucidating the specific mechanism of HCC. METHODS: Yeast two-hybrid test was conducted to screen proteins that interacted with Tiam1 gene. Glutathione-S-transferase (GST) pull-down and crosslinking-immunoprecipitation (CLIP) assays were performed to determine whether SETDB1 can interact with Tiam1 gene. A series of related experiments were performed to explore role of SETDB1 on cell proliferation, migration, and invasion in HCC. Recovery experiment was performed to investigate the effect of Tiam1 knockdown on cell proliferation and migration, which was caused by SETDB1 overexpression in HCC cells. The expression of SETDB1 was frequently upregulated in HCC tissues and positively correlated with Tiam1. RESULTS: GST pull-down and CLIP assays were performed to elucidate the interaction between SETDB1 and Tiam1. Cell proliferation, migration, and epithelial mesenchymal transformation (EMT) in HCC cells was promoted with the overexpression of SETDB1. Following the knockdown of Tiam1 gene, the effect of SETDB1 on cell proliferation and migration was reversed in HCC cells. The expression of SETDB1 was frequently up-regulated in HCC tissues, and it was positively correlated with Tiam1 gene. CONCLUSIONS: Ours is the first study to prove that SETDB1 promotes the proliferation and migration of cells by forming SETDB1-Tiam1 compounds. We found that SETDB1-Tiam1 compounds were involved in a novel pathway, which regulated epigenetic modification of gene expression in HCC samples.

11.
Biotechnol Biofuels ; 11: 72, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29560027

RESUMO

Background: Pyrolysis has attracted growing interest as a versatile means to convert biomass into valuable products. Wheat straw has been considered to be a promising biomass resource due to its low price and easy availability. However, most of the products obtained from wheat straw pyrolysis are usually of low quality. Hot soda extraction has the advantage of selective dissolution of lignin whilst retaining the carbohydrates. This can selectively convert biomass into high-quality desired products and suppress the formation of undesirable products. The aim of this study was to investigate the pyrolysis properties of wheat straw under different hot caustic pretreatment conditions. Results: Compared with the untreated straw, a greater amount of gas was released and fewer residues were retained in the extracted wheat straw, which was caused by an increase in porosity. When the NaOH loading was 14%, the average pore size of the extracted straw increased by 12% and the cumulative pore volume increased by 157% compared with the untreated straw. The extracted straw obtained from the 14% NaOH extraction was clearly selective for pyrolysis products. On one hand, many lignin pyrolysis products disappeared, and only four main lignin-unit-pyrolysis products were retained. On the other hand, polysaccharide pyrolysis products were enriched. Both propanone and furfural have outstanding peak intensities that could account for approximately 30% of the total pyrolysis products. However, with the excessive addition of NaOH (i.e. > 22% w/w) during pretreatment, the conversion of bio-gas products decreased. Thermogravimetric and low-temperature nitrogen-adsorption analysis showed that the pore structure had been seriously destroyed, leading to the closing of the release paths of the bio-gas and thus increasing the re-polymerisation of small bio-gas molecules. Conclusions: After suitable extraction (14% NaOH loading extraction), a considerable amount (25%) of the soluble components dissolved out of the straw. This resulted in an increase in both pore size and volume. This condition appeared to be optimally selective for the release of value-added pyrolysis products such as furfural, ketones and lignin monomer units. However, excessive addition of alkali (22%) for extraction could change the original interior structure, resulting in a decrease in both pore size and volume. This interior structure modification limited the release of pyrolysis products, and greater carbonisation occurred.

12.
Biomed Pharmacother ; 99: 245-252, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29334668

RESUMO

The Lidanpaidu Prescription (LDP), a hospital preparation, composed of Chinese classical preparations, has been reported to have antiendotoxin, anticoagulant and other effects. However, its therapeutic effect on lipopolysaccharide (LPS)-induced acute kidney injury (AKI) and the mechanisms remain unclear. Therefore, we administered LPD pretreatment at different doses to examine the protective effects and mechanisms in LPS-induced AKI in mice. The kidney injury induced by LPS was assessed by histological examination. ELISA was used to detect the levels of inflammatory cytokines. The mRNA expression of the inflammatory genes IKKß and TNF-α in kidney tissues was assessed by RT-PCR. Finally, Western blot was performed to assess the NF-κB signaling pathway related proteins, and the nuclear translocation of NF-kB P65 was detected by immunofluorescence laser confocal microscopy. The findings suggested that LDP significantly improved at 48 h animal survival (66.7%), compared with the LPS group (26.7%), determined by a Kaplan-Meier analysis. LDP attenuated the kidney histopathological changes induced by LPS and decreased the inflammatory cytokine levels in serum and renal tissue. Moreover, LDP markedly inhibited the expression of inflammatory genes and suppressed the activation of relevant proteins in the nucleus. In summary, these findings suggest that LDP reduces LPS-induced AKI via a mechanism related to the suppression of the NF-κB signaling pathway.


Assuntos
Lesão Renal Aguda/tratamento farmacológico , Lesão Renal Aguda/metabolismo , Medicamentos de Ervas Chinesas/uso terapêutico , NF-kappa B/metabolismo , Transdução de Sinais , Lesão Renal Aguda/sangue , Lesão Renal Aguda/induzido quimicamente , Animais , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Citocinas/sangue , Citocinas/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Quinase I-kappa B/genética , Quinase I-kappa B/metabolismo , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos , Camundongos Endogâmicos BALB C , Substâncias Protetoras/farmacologia , Substâncias Protetoras/uso terapêutico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sepse/sangue , Sepse/complicações , Sepse/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Análise de Sobrevida , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
13.
Carbohydr Polym ; 181: 450-459, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29253996

RESUMO

In current study, cellouronic acid sodium (CAS), obtained from bagasse pith, has been introduced into poly(acrylamide-co-diallyldimethylammonium chloride) (poly(AM-co-DAC)) network to form novel thermo-sensitive semi-IPNs. The structure and morphology of the hydrogels were proved by Fourier transformation infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The effects of CAS content, initiator charge, cross-linker dosage and swelling-medium property on the thermo-responsive water absorptivity were investigated in detail. The results elucidated that the prepared gels exhibited a thermo-sensibility with an upper critical solution temperature (UCST) and a high water-absorbency. And the values of UCST and equilibrium swelling ratio largely depended on the inner structure of the semi-IPNs and the external solvent property. It was also revealed that the swelling process conformed to the Schott's pseudo second order model and diffusion type was non-Fickian diffusion. The value of activation energy for this polyelectrolyte was found to be 8.74kJ/mol.

14.
Spectrochim Acta A Mol Biomol Spectrosc ; 193: 133-140, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29223458

RESUMO

Near-infrared (NIR) spectroscopy has been widely used in the analysis fields of traditional Chinese medicine. It has the advantages of fast analysis, no damage to samples and no pollution. In this research, a fast quantitative model for zinc oxide (ZnO) content in mineral medicine calamine was explored based on NIR spectroscopy. NIR spectra of 57 batches of calamine samples were collected and the first derivative (FD) method was adopted for conducting spectral pretreatment. The content of ZnO in calamine sample was determined using ethylenediaminetetraacetic acid (EDTA) titration and taken as reference value of NIR spectroscopy. 57 batches of calamine samples were categorized into calibration and prediction set using the Kennard-Stone (K-S) algorithm. Firstly, in the calibration set, to calculate the correlation coefficient (r) between the absorbance value and the ZnO content of corresponding samples at each wave number. Next, according to the square correlation coefficient (r2) value to obtain the top 50 wave numbers to compose the characteristic spectral bands (4081.8-4096.3, 4188.9-4274.7, 4335.4, 4763.6,4794.4-4802.1, 4809.9, 4817.6-4875.4cm-1), which were used to establish the quantitative model of ZnO content using back propagation artificial neural network (BP-ANN) algorithm. Then, the 50 wave numbers were operated by the mean impact value (MIV) algorithm to choose wave numbers whose absolute value of MIV greater than or equal to 25, to obtain the optimal characteristic spectral bands (4875.4-4836.9, 4223.6-4080.9cm-1). And then, both internal cross and external validation were used to screen the number of hidden layer nodes of BP-ANN. Finally, the number 4 of hidden layer nodes was chosen as the best. At last, the BP-ANN model was found to enjoy a high accuracy and strong forecasting capacity for analyzing ZnO content in calamine samples ranging within 42.05-69.98%, with relative mean square error of cross validation (RMSECV) of 1.66% and coefficient of determination (R2) of 95.75% in internal cross and relative mean square error of prediction (RMSEP) of 1.98%, R2 of 97.94% and ratio of performance to deviation (RPD) of 6.11 in external validation.


Assuntos
Algoritmos , Compostos Férricos/análise , Minerais/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Óxido de Zinco/análise , Calibragem , Combinação de Medicamentos , Análise dos Mínimos Quadrados , Redes Neurais (Computação)
15.
Zhongguo Zhong Yao Za Zhi ; 42(18): 3639-3644, 2017 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-29218954

RESUMO

Gastrodia elata has been used in China for more than 2 000 years and it is a kind of valuable traditional Chinese medicine. The originrecords of G. elata were Mount Tai of Shandong and and Mount Song of Henan, which began in Wupu Bencao of Wei Jin Dynasties, and Tai'an and its surrounding areas had been the Do-di herbs production areas. But from the beginning of the Republic of China, G. elata origin has undergone major changes, Do-di herbs production areas moved westward to the southwest.In this paper,through literature research and field visits, we studied the formation and changes of Do-di herbs production areas of G. elata. The cultivation history and current main producing area of G. elata was also introduced. On this basis, we profoundly summarized the reasons of Do-di herbs production areas formation and changes from the nature, society, transportation, humanities and germplasm resources.Combining the ancient herbal medicine and the characteristics of modern producing areas, the planting strength of G. elata could be strengthened in the hope of providing reference for the quality evaluation and cultivation of G. elata.

16.
J Cancer ; 8(16): 3318-3330, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29158805

RESUMO

SETDB1 is a novel histone methyltransferase associated with the functional tri-methylation of histone H3K9. Although aberrant high expression of SETDB1 was experimentally obversed in a variety of solid tumors, its underlying mechanisms in human carcinogenesis are not well known. In this study, we investigated the expression of SETDB1 in a large cohort of colorectal cancer (CRC) samples and cell lines for the first time. Our findings showed that SETDB1 was highly expressed in majority CRC tissues and cell lines; moreover, up-regulation of SETDB1 was negatively correlated with the survival rate of CRC patients. Functionally, over-expression of SETDB1 significantly promoted the proliferation and migration of CRC cells in vitro and in vivo, while knocking down SETDB1 suppressed their growth. Mechanistically, we showed that over-expression of SETDB1 significantly inhibited the apoptosis induced by 5-Fluorouracil in CRC cells, which was closely related to the inhibition of TP53 and BAX expression. Furthermore, we confirmed that SETDB1 could be recruited to the promoter region of TP53, which might contribute its inhibition of apoptosis. For conclusion, our study indicated that SETDB1 is essential for colorectal carcinogenesis, and may be a newly target for treatment and prognostic evaluation in CRC.

17.
Sci Rep ; 7(1): 16032, 2017 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-29167482

RESUMO

The centipede Scolopendra has important medicinal value and high toxicity, making it to be an interesting subject for evolutionary studies. However, species identification in China is difficult because of limited resource exploration and lack of recent taxonomic revision. To improve the identification and taxonomy of the genus Scolopendra in China, an in-depth investigation was conducted, and an integrated method that combined morphological characteristics with molecular data was applied. The identification key was revised to show the main difference among species. Our results indicated that morphologically-delimited species were consistent with the molecular analysis inferred from the COI sequences with genetic distances and phylogenetic trees. Additional morphometrics of four characteristics provided criteria for shape variation. These results suggested that the members of the genus Scolopendra in China could be delineated as 14 separate species. A new species from Lufeng county, Yunnan province, was proposed according to its characteristics, which was named as S. lufengia sp. nov. Our results comprehensively ascertained the taxonomic status of Scolopendra species in China, explored their phylogenetic relationships, showed a high success in the identification of medicinal centipedes.

18.
Carbohydr Polym ; 178: 412-417, 2017 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-29050613

RESUMO

In this study, a reutilization of caustic lye during cold caustic extraction (i.e., CCE) process to produce high-purity dissolving pulp and high-concentrated hemicellulose solution was proposed. The results showed that the lye can be reused about 12 times for producing high-purity dissolving pulps. With the number of CCE stages of 12, the hemicellulose in the lye can be auto-concentrated to about 37g/L. The alkali efficiency of the modified CCE process was about 6 (or 3) times better than the traditional CCE process with low- (or middle-) consistency of pulps. Therefore, the present process is feasible to be used for the purification of dissolving pulps with a cost-effective manner.

19.
Oncotarget ; 8(39): 65717-65729, 2017 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-29029466

RESUMO

Resveratrol and caloric restriction (CR) are the powerful therapeutic options for anti-aging. Here, their comparative effect on longevity-associated gene silencing information regulator (SIRT1) were evaluated in vitro and in vivo. IMR-90 cells treated with 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) were applied to establish a cellular senescence model, and rats treated with D-galactose (D-gal) were used as an aging animal model. Resveratrol and CR exhibited similar anti-aging activities, evidenced by inhibiting senescence and apoptosis, and restoring cognitive impairment and oxidative damage. Moreover, they could up-regulate telomerase (TE) activity, increase expressions of SIRT1, forkhead box 3a (Foxo3a), active regulator of SIRT1 (AROS) and Hu antigen R (HuR ), but decrease p53 and deleted in breast cancer 1 (DBC1) levels. However, 10 µM resveratrol in vitro and the high dose group in vivo showed relatively stronger activities of anti-aging and stimulating SIRT1 level than CR. In conclusion, resveratrol and CR showed similar anti-aging activities on SIRT1 signaling, implicating the potential of resveratrol as a CR mimetic.

20.
Appl Spectrosc ; 71(11): 2427-2436, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28758413

RESUMO

In this research paper, a fast, quantitative, analytical model for magnesium oxide (MgO) content in medicinal mineral talcum was explored based on near-infrared (NIR) spectroscopy. MgO content in each sample was determined by ethylenediaminetetraacetic acid (EDTA) titration and taken as reference value of NIR spectroscopy, and then a variety of processing methods of spectra data were compared to establish a good NIR spectroscopy model. To start, 50 batches of talcum samples were categorized into training set and test set using the Kennard-Stone (K-S) algorithm. In a partial least squares regression (PLSR) model, both leave-one-out cross-validation (LOOCV) and training set validation (TSV) were used to screen spectrum preprocessing methods from multiplicative scatter correction (MSC), and finally the standard normal variate transformation (SNV) was chosen as the optimal pretreatment method. The modeling spectrum bands and ranks were optimized using PLSR method, and the characteristic spectrum ranges were determined as 11995-10664, 7991-6661, and 4326-3999 cm-1, with four optimal ranks. In the support vector machine (SVM) model, the radical basis function (RBF) kernel function was used. Moreover, the full spectrum data of samples pretreated with SNV, the characteristic spectrum data screened using synergy interval partial least squares (SiPLS), and the scoring data of the first four ranks obtained by a partial least squares (PLS) dimension reduction of characteristic spectrum were taken as input variables of SVM, and the MgO content reference values of various sample were taken as output values. In addition, the SVM model internal parameters were optimized using the grid optimization method (GRID), particle swarm optimization (PSO), and genetic algorithm (GA) so that the optimal C and g-values were determined and the validation model was established. By comprehensively comparing the validation effects of different models, it can be concluded that the scoring data of the first four ranks obtained by PLS dimension reduction of characteristic spectrum were taken as input variables of SVM, and the PLS-SVM regression model established using GRID was the optimal NIR spectroscopy quantitative model of talc. This PLS-SVM regression model (rank = 4) measured that the MgO content of talcum was in the range of 17.42-33.22%, with root mean square error of cross validation (RMSECV) of 2.2127%, root mean square error of calibration (RMSEC) of 0.6057%, and root mean square error of prediction (RMSEP) of 1.2901%. This model showed high accuracy and strong prediction capacity, which can be used for rapid prediction of MgO content in talcum.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA